This application addresses broad Challenge Area (04): Clinical Research and specific Challenge Topic, 04-HL-104: "Perform secondary analyses of existing data to answer important clinical and preventive medicine research questions." Within this topic we address one of the example areas of interest: "Analyses of important demographic subgroups". African Americans have a shorter life expectancy than Whites and suffer higher rates of many chronic diseases. Life expectancy for African Americans in 2005 was 69.5 years for males and 76.5 years for females compared to 75.7 and 80.8 years, respectively, for Whites. It is important to understand the role that modifiable risk factors, such as obesity, play in the production of the observed excess burden of morbidity and mortality. Studies of the consequences of obesity in African Americans indicate marked differences in the associated co-morbidities compared to Whites. However, few longitudinal studies have studied hard endpoints such as coronary heart disease (CHD) and cardiovascular disease (CVD) or total mortality. In addition, our understanding of the consequences of changes in weight is limited, particularly in African Americans. We will use a population-based sample of African American and White men and women to examine associations of an obesity-related measure with fatal and non-fatal coronary heart disease (CHD), cardiovascular disease (CVD) and all-cause mortality. We will determine and compare (among ethnic-gender groups) the risks associated with body mass index (BMI) and waist circumference. We will also examine risks associated with long term weight change (over a minimum of 23 years) and distinguish this risk from that of short-term weight change that occurs close to the time of event. These aims will be met through the analyses of extant data from the Atherosclerosis Risk in Communities Study (ARIC). This study has collected information on over 15,000 participants including over 4,000 African Americans. Participants were studied in four clinic visits and a range of physiologic and behavioral risk factors were measured. Standardized information on vital status and incident CHD and stroke events is available with over 17.5 years of follow-up. The ARIC study arguably provides the best data set currently available for studies of obesity- related risk and hard cardiovascular endpoints in African Americans, and affords the opportunity to advance our understanding of this important public health problem in a population that is at increased risk. The results of this work will have immediate impact as they will be used to provide background information for the NHLBI Clinical Guidelines for Cardiovascular Risk Reduction, and will supplement the sparse information currently available in African Americans. This study will examine whether overweight and obese middle-aged adults are more likely to develop heart disease or die compared to normal weight middle-aged adults. We will also evaluate if the amount of weight change during middle-adulthood or since age 25 increases the likelihood of developing heart disease or dying. Comparisons will be made between African American women, African American men, White women and White men.